Mr Blair indicated he would not back down under pressure from Labour rebels, insisting the Education White Paper was essential to raise standards in schools.

Thomas Telford achieved the best GCSE results in the country last year when every pupils achieved 11 or more GCSEs graded between A* and C.

It beat the nation's leading independent and grammar schools, even though it is a state school with a mixedability intake.

In the past three years it has also helped turn around nearby Madeley Court School, also in Telford, a comprehensive with one of the worst records in the West Midlands.

Thomas Telford is a city technology college, which means that although it does not charge fees it is an independent school, and private sponsors such as Tarmac and the Mercers' Company have a majority of posts on the board of governors.

The Government's Education White Paper will create "trust schools", governed in a similar way to Thomas Telford. Successful trust schools will be encouraged to form federations with less successful schools.

Speaking at his regular Downing Street press conference, Mr Blair said: "Thomas Telford took over the poorest performing school in Telford.

"It used to have 50 youngsters applying for the 150 places available each year.

"In a short period of time, as a result of this federation, the percentage [at Madeley Court] getting five good GCSEs rose from 20 per cent to 50 per cent, and it is likely to reach 75 per cent this summer.

"And the intake is now full, in fact it is oversubscribed."

More than 90 Labour back-benchers have now said they oppose the Government's school reforms, more than enough to overturn the proposals in a Commons vote.

They are backed by senior party figures including John Prescott, the Deputy Prime Minister, Neil Kinnock, the former Labour leader, and Estelle Morris, the former Education Secretary.

There has been speculation Mr Blair would use a report by the Commons Education Committee, due this week, as an opportunity to compromise with rebels. But he appeared to rule that out, saying the reforms were "fundamental" to the Government.

"It is about everything to do with the politics of this Government. How we think, what we feel, what is our basic position."

Mr Blair said: "It's a bit of a highwire act . . . because I've got significant numbers of my own side who are against it."

But he had no intention of losing the legislation.

He said: "This reform is based on what works and it has at its core a very simple proposal to raise standards in our schools.

"It is to make sure that the schools that are failing and not offering children the best education are radically improved, that every average school becomes a good school, and that good schools are able to expand and develop in the way that they want."